Work Step by Step
The Fundamental Counting Principle: The number of ways in which a series of successive things can occur is found by multiplying the number of ways in which each thing can occur. --- 1. You can choose a 1st prize winner in 100 ways. 2. You can choose a 2nd prize winner (from the 99 remaining) in 99 ways Total ways = $100\times 99=9900$ ways.